超缓凝混凝土在长螺旋咬合桩中的应用  

Application of super-retarding concrete in long spiral bite pile

作　　者：刘世成 孙旭辉 徐升才 邹府兵 龚良勇 LIU Shicheng;SUN Xuhui;XU Shengcai;ZOU Fubing;GONG Liangyong(School of Infrastructure Engineering,Nanchang University,Nanchang 330031,China;Jiangxi Zhongheng Underground Interspace Science Co.,Ltd.,Nanchang 330052,China)

机构地区：[1]南昌大学工程建设学院,江西南昌330031 [2]江西中恒地下空间科技有限公司,江西南昌330052

出　　处：《南昌大学学报（工科版）》2023年第2期170-175,共6页Journal of Nanchang University(Engineering & Technology)

摘　　要：结合南昌某工程,以白糖和葡萄糖酸钠作为复合缓凝剂,采用一次搅拌和二次搅拌2种制备工艺,配制超缓凝混凝土。通过对流动性、凝结时间、抗压强度等方面的测试分析,确定C35超缓凝混凝土的最佳配合比;通过对微观形貌的测试分析,探究缓凝剂对水泥水化产物的影响。结果表明,掺入缓凝剂可以改变水泥早期水化产物钙矾石(AFt)的晶体结构,减缓水化速率,延长凝结时间。缓凝剂掺量为0.38%时,混凝土有较长的凝结时间,较好的流动性,以及较高的力学性能,满足实际工程的施工要求。相较于一次搅拌工艺,采用二次搅拌工艺制备的超缓凝混凝土,流动性更好,凝结时间更长,更有利于长螺旋咬合桩的施工应用。Combined with a project in Nanchang,white sugar and sodium gluconate were used as composite retarders,and the super-retarding concrete was prepared by two preparation processes of primary stirring and secondary stirring process.Through the test and analysis of fluidity,setting time and compressive strength,the optimum mix proportion of C35 super retarding concrete was determined.The influence of retarder on cement hydration products was investigated by testing and analyzing the micromorphology.The results showed that the addition of retarder can change the crystal structure of early hydration products(AFt)of cement,slow down the hydration rate and prolong the setting time.When the retarder content was 0.38%,the concrete has longer setting time,better fluidity and higher mechanical properties,which can meet the construction requirements of practical engineering.Compared with the primary stirring process,the super retarding concrete prepared by the secondary stirring process has better fluidity and longer setting time,which was more conducive to the construction and application of long spiral bite piles.

关 键 词：超缓凝混凝土 长螺旋咬合桩 二次搅拌 微观形貌 

分 类 号：TU528[建筑科学—建筑技术科学]